1. Department of Electrical Engineering and Computer Science, and Vanderbilt Institute of Nanoscale Science and Engineering, Vanderbilt University, Nashville, Tennessee 37232, United States
2. School of Electrical and Computer Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
3. Water Institute, Purdue University Northwest, Hammond, Indiana 46323, United States
4. School of Mechanical Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States